1. Field of the Invention
The present invention relates to a powertrain system and, more particularly, to a hybrid powertrain system including a transformer module having a planetary gearset.
2. Description of the Related Art
Hydrokinetic torque converters are commonly used in engine-driven vehicles and other equipment applications where a speed absorbing function (i.e., varying the output speed of the torque converter relative to the input speed) and a torque amplification function are desired. In automated vehicle powertrain systems, for example, it is common to position a torque converter between an engine and an automatic transmission. While hydrokinetic torque converters satisfactorily perform the torque amplification function, they are relatively inefficient at performing the speed absorbing function. For this and other reasons, a powertrain apparatus is needed that performs a speed absorbing function more efficiently than a hydrokinetic torque converter without limiting its ability to transfer torque.